Vaccine information for young children

Updated June 21, 2022

Have you and your child been vaccinated?

The COVID-19 vaccine for children as young as 6 months old is available to Pima County clinics. Making an appointment at one of the clinics is recommended to avoid a wait. Also, be sure to check with your pediatrician and pharmacies for availability.

The Pfizer series is available for children age 6 months through 4 years old. Moderna’s series is approved for children age 6 months through 5 years old. The Moderna series consists of two shots given four weeks apart. Pfizer’s series consists of two shots given three weeks apart, followed by a third shot eight weeks later.

“Vaccination is an important step to protect our smallest children from serious illness, long-term effects from COVID, and to help them from spreading the virus to adults and others in the family who are more vulnerable,” said Pima County Health Department Director Dr. Theresa Cullen.

COVID-19 vaccinations are safe and effective at preventing serious illness and hospitalization related to the COVID-19 virus. Getting children vaccinated against COVID-19 will also help prevent outbreaks in schools and ensure that classrooms and schools stay open.

Frequently asked questions on COVID-19 vaccinations for 6 months through 4 years old

Why should children under 5 get vaccinated?

Infants and children under 5 are at serious risk from COVID-19. During the omicron surge, children under 5 were hospitalized at five times the rate than during delta. Half of those were previously healthy. As of June 2, 2022, COVID-19 killed 442 children ages 0-4 years, and deaths in this age group due to COVID-19 are higher than from other vaccine-preventable diseases.

We already know from vaccinations in 5- to 17-year olds, that hospitalization and death are more common in children who are not vaccinated and boosted. Young children who get COVID-19 are at risk of MIS-C, a serious multisystem inflammatory syndrome, and children can get long COVID. The CDC offers more about the risks of COVID-19 in children 6 months to 17 years.

The Moderna and Pfizer studies found that vaccinated children ages 6 months to 5 years had fewer infections. Reducing the chance of infection also helps keep children from missing school or daycare, and from spreading the virus to others in their household, family and community.

See the CDC’s recommendations for COVID-19 vaccination in children and teens.

Which vaccines are available for those 6 months to 5 years, and what are the differences?

The FDA’s June 17, 2022 Emergency Use Authorizations allow parents to choose between COVID-19 vaccines by Moderna or Pfizer. Current guidance from the CDC recommends Pfizer or Moderna for those 6 months to 5 years old. Children under 5 who get the Pfizer vaccine will need 3 vaccine doses.

Both vaccines were found to be safe and reduced infection rates from 37-80%. See a summary of evidence by health experts and Brown University School of Public Health.

How are the dosages for this age group different from the adult dose?

The Pfizer vaccine for children 6 months to 4 years is one-tenth of the adult dosage, while the Moderna vaccine for children 6 months to 5 years is a quarter of the adult dosage.

If I was vaccinated during pregnancy, should I vaccinate my baby?

Getting vaccinated during pregnancy is an effective way to help protect yourself and your newborn against serious outcomes from COVID-19. A recent Harvard study suggested that antibody levels transferred to the newborn infant from a vaccinated mother may persist in a majority of infants to at least six months of age, which is when your child first becomes eligible for COVID-19 vaccination. Talk to your pediatrician for questions about the optimal timing of your baby’s vaccination.

My child is turning 5 soon, should I wait to have them vaccinated with the higher dose?

It is better to vaccinate when your child becomes eligible, rather than wait and risk infection. The vaccine is dosed according to age, so your child will always receive the appropriate dose, regardless of how old they are.

If my child already had COVID-19, should I still get them vaccinated?

Yes, because not everyone develops protection after infection. A recent study suggests that 32% of children did not generate protective antibodies against a confirmed COVID-19 infection. Previous studies in adults have shown that the “hybrid immunity” resulting from infection plus vaccination results in broad protection across different parts of the immune system. (This does not mean you should intentionally seek out infection for your child, since the virus carries serious risks for severe outcomes that the vaccine does not.)

Frequently asked questions on COVID-19 vaccinations for 5 to 11-year-olds

When should 5-11 year olds get a booster?

On May 19, 2022, the CDC expanded booster eligibility to include 5-11 year olds, and recommends they receive a Pfizer booster five months after completion of their primary vaccine series.

Where can I take my child for a COVID-19 vaccination?

Here's what parents can do:
    Go to or check with your local pharmacy to see if vaccination walk-ins or appointments are available for children. You can also check at
  • Check with your child’s healthcare provider about whether they offer COVID-19 vaccination.
  • The pediatric vaccine is available at Pima County Public Health Clinics, Abrams Public Health Center, and at various mobile sites, including school locations. Find locations and hours of operation for County sites at

How is this dose different from those given to 12 and older?

The Pfizer dose administered to children aged 5-11 is a lower dose. It contains only one-third of the dose given to those 12 and older, and a second dose is given 21 days later.

What side effects, if any, are expected in this age group?

The most common side effects reported in the clinical studies were pain at the injection site, tiredness, headache, fever, and muscle and joint pain. When these occurred, they were generally gone within 1-3 days. In the reports submitted to the FDA, the vaccine manufacturer noted that these side effects were generally milder and occurred less frequently than in adolescents. In 5-11 year-old participants, there were no instances of heart inflammation (myocarditis and pericarditis), that has very rarely occurred in some older adolescents and young adults, primarily among young males aged 16-29.

Why should 5- to 11-year-olds get vaccinated if they tend to not get as seriously ill as older people?

Although most do not become as seriously ill as adults, they run the same risk of becoming infected and thus risk complications. Since the start of the pandemic, almost 2 million children ages 5-11 have been infected, more than 8,300 have been hospitalized, and 94 have died, according to CDC data. The death toll makes COVID-19 one of the top 10 causes of death for this age group. MIS-C, the serious condition that causes inflammation in body organs, is most frequent among children ages 5-11 years infected with COVID-19. Children can also suffer from long-COVID conditions. The number of children becoming infected is increasing, due to the Delta variant. Even if they do not have symptoms, they can spread infection to other vulnerable people, perpetuating further infection.

How does the dosage work for children? What should a parent do if a child turns 12 after they get their first dose of the pediatric virus but before the second is due?

As opposed to many medications, vaccine dosages are based on age and not size or weight. If a child turns from 11 to 12 years of age in between their first and second dose, the second dose should be the Pfizer vaccine for adolescents and adults. However, if the child receives the Pfizer vaccine for children ages 5 through 11 years for their second dose, they do not need to repeat the dose. 

Parent videos: Why getting your child vaccinated is important

COVID-19 and kids: How mRNA vaccines works

Other parent resources

Follow Us Share this page

Health Department

3950 S. Country Club Road
Ste. 100
Tucson, AZ 85714

(520) 724-7770

Department Home
Department News
Department Directory

phab logo